Early clinical outcomes of wavefront-guided myopic LASIK treatments using a new-generation hartmann-shack aberrometer

Comparison of the 1st Generation and 3rd Generation Wavefront-Guided LASIK for the Treatment of Myopia and Myopic Astigmatism

Purpose

To compare refractive, visual, and patient-reported outcomes associated with a 1st generation wavefront-guided (WFG) treatment with those associated with a 3rd generation WFG treatment.

Patients and Methods

This retrospective study included patients who underwent femtosecond laser-assisted in situ keratomileusis (LASIK) for myopia/myopic astigmatism. Two random stratified samples of patients who underwent either 1stgeneration (WaveScan, Johnson & Johnson Vision, Santa Ana, CA) or 3rd generation (iDesign 2.0, Johnson & Johnson Vision, Santa Ana, CA) treatment matched on preoperative refraction were compared (4290 eyes of 2145 patients in each group). One-month postoperative visual, refractive, and patient-reported outcomes were analyzed. Refractive and monocular visual acuity analyses were performed using one random eye of each patient.

Results

The percentage of eyes achieving 20/20 or better uncorrected vision was 91.3% (1958/2145) in the 1st generation group and 95.9% (2056/2145) in the 3rd generation group (p<0.01). Binocularly, the percentage of patients with 20/20 or better UDVA was 97.0% (2080/2145) and 99.2% (2127/2145) in the 1st and 3rd generation groups, respectively (p<0.01). The mean postoperative MSE was -0.01 ± 0.33 D in the 1st generation group and +0.19 ± 0.33 D in the 3rd generation group (p<0.01). Postoperative refractive astigmatism had a mean value of -0.20 ± 0.26 D and -0.18 ± 0.24 D in the 1st and 3rd generation groups, respectively (p<0.01). The mean correction index of refractive astigmatism was 1.09 ± 0.53 in the 1st generation group and 1.02 ± 0.38 in the 3rd generation group, p<0.01. The overall percentage of patients satisfied with vision was 92.8% (1991/2145 patients) in the 1st generation group and 97.3% (2087/2145 patients) in the 3rd generation group (p<0.01).

Conclusion

For the majority of postoperative variables, there were significant differences between 1st and 3rd generation treatments. The 3rd generation treatments had better visual acuity outcomes and higher patient satisfaction.

Patient reported outcomes for phosphomannomutase 2 congenital disorder of glycosylation (PMM2-CDG): listening to what matters for the patients and health professionals

Background

Congenital disorders of glycosylation (CDG) are a growing group of rare genetic disorders. The most common CDG is phosphomannomutase 2 (PMM2)-CDG which often has a severe clinical presentation and life-limiting consequences. There are no approved therapies for this condition. Also, there are no validated disease-specific quality of life (QoL) scales to assess the heterogeneous clinical burden of PMM2-CDG which presents a challenge for the assessment of the disease severity and the impact of a certain treatment on the course of the disease.

Aim and methods

This study aimed to identify the most impactful clinical signs and symptoms of PMM2-CDG, and specific patient and observer reported outcome measures (PROMs and ObsROMs, respectively) that can adequately measure such impact on patients’ QoL. The most burdensome signs and symptoms were identified through input from the CDG community using a survey targeting PMM2-CDG families and experts, followed by family interviews to understand the real burden of these symptoms in daily life. The list of signs and symptoms was then verified and refined by patient representatives and medical experts in the field. Finally, a literature search for PROMs and ObsROMs used in other rare or common diseases with similar signs and symptoms to those of PMM2-CDG was performed.

Results

Twenty-four signs/symptoms were identified as the most impactful throughout PMM2-CDG patients’ lifetime. We found 239 articles that included tools to measure those community-selected PMM2-CDG symptoms. Among them, we identified 80 QoL scales that address those signs and symptoms and, subsequently, their psychometric quality was analysed. These scales could be applied directly to the PMM2-CDG population or adapted to create the first PMM2-CDG-specific QoL questionnaire.

Conclusion

Identifying the impactful clinical manifestations of PMM2-CDG, along with the collection of PROMs/ObsROMs assessing QoL using a creative and community-centric methodology are the first step towards the development of a new, tailored, and specific PMM2-CDG QoL questionnaire. These findings can be used to fill a gap in PMM2-CDG clinical development. Importantly, this methodology is transferable to other CDG and rare diseases with multiple signs and symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02551-y.

Optical inspection of single vision soft contact lenses based on an active adaptive wavefront sensor

We present an experimental configuration for optical inspection of single vision soft contact lenses based on an active adaptive wavefront sensor. At first, the soft lenses were immersed in a saline filled wet cell to prevent surface deformation during measurements. Thereafter, refractive powers and aberrations were accurately measured before and after correcting illumination laser beam aberrations and wet cell-induced aberrations. The results reveal that there is a significant difference between the measured aberrations and refractive powers before and after aberration compensation. Accordingly, the proposed system is recommended as an optical inspection tool for precise assessment of commercially available contact lenses.

Wavefront-guided myopic laser in situ keratomileusis with a high-resolution Hartmann-Shack aberrometer and a new nomogram

PURPOSE

To evaluate visual, refractive, aberrometric, and patient-reported outcomes of wavefront-guided (WFG) myopic laser in situ keratomileusis (LASIK) using a high-resolution Hartmann-Shack aberrometer (iDesign Advanced WaveScan system) with a new nomogram and to determine whether the new nomogram resolved the mild undercorrection that occurs with the manufacturer's default settings.

SETTING

Three private LASIK practices.

DESIGN

Prospective, open-label, noncomparative, multicenter study.

METHODS

One hundred ninety eyes of 95 patients underwent bilateral WFG LASIK for the correction of myopia or myopic astigmatism. A new nomogram was used, which effectively adjusted the wavefront-measured refraction sphere up or down to equal the manifest refraction sphere. Patients were followed up for 6 months.

RESULTS

Eighty-four patients completed the final follow up. At 6 months, 162 (96.4%) of 168 eyes achieved monocular uncorrected distance visual acuity of 20/20 or better. No eye lost 2 or more lines of corrected distance visual acuity. The safety and efficacy indices were 1.12 and 1.09, respectively; 164 (98%) of 168 eyes had manifest refraction spherical equivalent within ±0.50 diopters (D) of emmetropia, and 154 (92%) of 168 eyes had residual manifest refractive astigmatism of 0.50 D or less. Fewer patients experienced burning, stinging, soreness, and irritation postoperatively than preoperatively. Eighty-one (96%) of 84 patients reported improved quality of life.

CONCLUSIONS

WFG myopic LASIK using a high-resolution Hartmann-Shack aberrometer and a new nomogram resolved the undercorrection with the manufacturer's default settings. The treatment was safe and effective with excellent visual and refractive outcomes, high patient satisfaction, and improved quality of life.

Shack-Hartmann wavefront sensor optical dynamic range

The widely used lenslet-bound definition of the Shack-Hartmann wavefront sensor (SHWS) dynamic range is based on the permanent association between groups of pixels and individual lenslets. Here, we formalize an alternative definition that we term optical dynamic range, based on avoiding the overlap of lenslet images. The comparison of both definitions for Zernike polynomials up to the third order plus spherical aberration shows that the optical dynamic range is larger by a factor proportional to the number of lenslets across the SHWS pupil. Finally, a pre-centroiding algorithm to facilitate lenslet image location in the presence of defocus and astigmatism is proposed. This approach, based on the SHWS image periodicity, is demonstrated using optometric lenses that translate lenslet images outside the projected lenslet boundaries.

Multi-layer Shack-Hartmann wavefront sensing in the point source regime

The Shack-Hartmann wavefront sensor (SHWS) is often operated under the assumption that the sensed light can be described by a single wavefront. In biological tissues and other multi-layered samples, secondary wavefronts from axially and/or transversely displaced regions can lead to artifactual aberrations. Here, we evaluate these artifactual aberrations in a simulated ophthalmic SHWS by modeling the beacons that would be generated by a two-layer retina in human and mouse eyes. Then, we propose formulae for calculating a minimum SHWS centroid integration area to mitigate these aberrations by an order of magnitude, potentially benefiting SHWS-based metrology and adaptive optics systems such as those used for retinal imaging and microscopy.

Average gradient of Zernike polynomials over polygons

Wavefront estimation from slope sensor data is often achieved by fitting measured slopes with Zernike polynomial derivatives averaged over the sampling subapertures. Here we discuss how the calculation of these average derivatives can be reduced to one-dimensional integrals of the Zernike polynomials, rather than their derivatives, along the perimeter of each subaperture. We then use this result to derive closed-form expressions for the average Zernike polynomial derivatives over polygonal areas, only requiring evaluation of polynomials at the polygon vertices. Finally, these expressions are applied to simulated Shack-Hartmann wavefront sensors with 7 and 23 fully illuminated lenslets across a circular pupil, with their accuracy and calculation time compared against commonly used integration methods.

Prospective, Randomized, Contralateral Eye Comparison of Wavefront-Guided and Wavefront-Optimized Laser in Situ Keratomileusis

PURPOSE

To compare outcomes in wavefront-optimized (WFO) laser in situ keratomileusis (LASIK) to high-resolution wavefront-guided (WFG) LASIK.

DESIGN

Randomized, fellow eye controlled, clinical trial.

METHODS

A total of 200 eyes of 100 patients with myopia or compound myopic astigmatism undergoing bilateral LASIK between October 2015 and February 2017 underwent wavefront-optimized (WFO) LASIK in 1 eye and wavefront-guided (WFG) LASIK in the fellow eye. Each eye was evaluated for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, refractive error, and wavefront aberrometry. Outcome measurement primarily UDVA at 12 months. Secondary outcomes were safety, predictability, stability, refractive error, CDVA, contrast sensitivity, and higher-order aberrations at 12 months.

RESULTS

WFG LASIK had higher levels of supervision and better contrast sensitivity compared to WFO. Both types had excellent postoperative UDVA results, without a significant difference in either mean UDVA or frequency of achieving a specified UDVA, for example, 20/16 or better (all P > 0.05). The mean gain in lines of CDVA was significantly higher in the WFG than in the WFO group (0.80 ± 0.75 vs 0.62 ± 0.72, respectively; P = 0.04). The WFG cohort had significantly better contrast sensitivity for mean and frequency of achieving >20/40 for <5% low-contrast sensitivity (37.1%; 95% confidence interval [CI], 27.5-46.7 vs 24.7%; 95% CI, 16.2-33.3, respectively; P = 0.01) and >20/32 for <25% low-contrast sensitivity (10.3%; 95% CI, 4.3-16.4 vs 4%, respectively; 95% CI, 0.0-8.1, respectively; P = 0.04). The WFO group had a significantly higher frequency of <0.25 diopters (D) of refractive astigmatism at 12 months (82.5%; 95% CI, 75.0-90.0; vs 72.1%, respectively; 95% CI, 63.2-81.2; P = 0.02) but not <0.50 D (95.6%; 95% CI, 91.9-99.8; vs 96.9, respectively; 95% CI, 93.5-100; P = 0.61). The WFG group was significantly closer to emmetropia for both sphere and spherical equivalents at all time points. Trefoil was significantly lower in the WFG group and was also significantly lower than preoperative measurements.

CONCLUSIONS

Wavefront-optimized and high-resolution wavefront-guided LASIK achieve excellent visual outcomes. Nonetheless, treatments based on a high-resolution aberrometer appear to offer superior results in some regards.

Clinical outcomes of small-incision lenticule extraction and femtosecond laser-assisted wavefront-guided laser in situ keratomileusis

Small-incision lenticule extraction and wavefront-guided femtosecond-assisted laser in situ keratomileusis (LASIK) provide good visual outcomes and an efficacious correction of myopia or myopic astigmatism with similar levels of safety. Some differences in predictability and the percentage of eyes gaining lines of corrected distance visual acuity are present. A higher level of coma is present after small-incision lenticule extraction, with no clear differences between techniques in spherical aberration. Better contrast sensitivity is achieved in the early postoperative period after wavefront-guided femtosecond laser-assisted LASIK, possibly because of less intrastromal light backscattering and Bowman layer microdistortions. Corneal sensitivity decreased less after small-incision lenticule extraction because of less severe decrease in subbasal nerve density, which has a significant effect on symptomatology and dry-eye tests (P < .05). Significant corneal biomechanical changes occurred after both techniques (P < .05), with no scientific evidence supporting the superiority of 1 technique over the other.

FINANCIAL DISCLOSURE

Dr. Piñero received an unrestricted educational grant from Abbott Medical Optics, Inc. Neither author has a financial or proprietary interest in any material or method mentioned.

Recent advances in wavefront-guided LASIK

PURPOSE OF REVIEW

Laser vision correction remains an active area of research, and there have been many recent advances in the field. The purpose of this review is to provide an update on the recent advances for one of the most common methods of laser vision correction, wavefront-guided laser in-situ keratomileusis (LASIK).

RECENT FINDINGS

Recent technological advancements in wavefront aberrometry are largely responsible for the improved visual outcomes that have been recently reported. In addition, improvements in femtosecond and excimer laser technology, used in flap creation and corneal ablation, have been shown to provide superior results when compared to microkeratomes and earlier lasers. Wavefront-guided LASIK appears to have advantages over some other keratorefractive modalities in terms of visual acuity, predictability, astigmatism correction, and subjective visual symptoms. Nonetheless, there may be some limitations in highly aberrated corneas, and also in biomechanical stability relative to other available platforms.

SUMMARY

Improvements in wavefront aberrometry, and also femtosecond and excimer lasers, have continued to improve our ability to correct refractive errors. Wavefront-guided LASIK remains a well tolerated and effective keratorefractive procedure, with a trend toward superiority. Nonetheless, further studies comparing this modality to others are needed to define the role each can serve.

High-resolution wavefront-guided surface ablation with corneal cross-linking in ectatic corneas: a pilot study

Purpose

A preliminary study to evaluate the outcomes of high-resolution wavefront-guided (HRWG) photorefractive keratectomy (PRK) with simultaneous corneal cross-linking (CXL) in ectasia eyes.

Methods

Sixteen eyes of 11 patients (mean age 31.9±9.8 years; range: 15–48 years) with keratoconus or post-laser-assisted in situ keratomileusis ectasia underwent HRWG PRK with simultaneous CXL. Manifest refraction, uncorrected (UDVA) and corrected distance visual acuity (CDVA), and keratometric and aberrometric outcomes are reported at 12 months.

Results

Significant improvement was observed postoperatively in visual acuity, refraction, and keratectomy in all eyes. At postoperative 12 months, 87.5% eyes were within ±1.0 D of attempted correction and 81.25% of eyes had a postoperative UDVA of 20/32 or better. A gain of 2 or more lines of CDVA was observed in 12.5% (2/16) of eyes and there was no change in CDVA lines in 25% (4/16) eyes. A substantial reduction in higher-order aberrations was observed in all eyes postoperatively; however, the improvement was not statistically significant.

Conclusion

The outcomes of HRWG PRK in ectasia eyes with estimated residual stromal bed thickness of at least 350 μm (without epithelium) are promising at postoperative 1 year and provide surgeons with a valuable tool to improve vision with a high degree of refractive predictability.

Polar Value Analysis of Low to Moderate Astigmatism with Wavefront-Guided Sub-Bowman Keratomileusis

Purpose

To evaluate the astigmatic outcomes of wavefront-guided sub-Bowman keratomileusis (WFG-SBK) for low to moderate myopic astigmatism.

Methods

This study enrolled 100 right eyes from 100 patients who underwent WFG-SBK for the correction of myopia and astigmatism. The polar value method was performed with anterior and posterior corneal astigmatism measured with Scheimpflug camera combined with Placido corneal topography (Sirius, CSO) and refractive astigmatism preoperatively and 1 month, 3 months, and 6 months postoperatively.

Results

Similar results for surgically induced astigmatism (SIA) and error of the procedure in both anterior corneal astigmatism (ACA) and total ocular astigmatism (TOA). There was a minor undercorrection of the cylinder in both ACA and TOA. Posterior corneal astigmatism (PCA) showed no significant change.

Conclusions

Wavefront-guided SBK could provide good astigmatic outcomes for the correction of low to moderate myopic astigmatism. The surgical effects were largely attributed to the astigmatic correction of the anterior corneal surface. Posterior corneal astigmatism remained unchanged even after WFG-SBK for myopic astigmatism. Polar value analysis can be used to guide adjustments to the treatment cylinder alongside a nomogram designed to optimize postoperative astigmatic outcomes in myopic WFG-SBK.

Repeatability and Agreement of Central Corneal Thickness and Keratometry Measurements between Four Different Devices

Background. To estimate repeatability and comparability of central corneal thickness (CCT) and keratometry measurements obtained by four different devices in healthy eyes. Methods. Fifty-five healthy eyes from 55 volunteers were enrolled in this study. CCT (IOLMaster 700, Pentacam HR, and Cirrus HD-OCT) and keratometry readings (IOLMaster 700, Pentacam HR, and iDesign) were measured. For statistical analysis, the corneal spherocylinder was converted into power vectors (J0, J45). Repeatability was assessed by intraclass correlation coefficient (ICC). Agreement of measurements between the devices was evaluated by the Bland-Altman method. Results. The analysis of repeatability of CCT data of IOLMaster 700, Pentacam HR, and Cirrus HD-OCT showed high ICCs (range 0.995 to 0.999). The comparison of CCT measurements revealed statistically significant differences between Pentacam HR versus IOLMaster 700 (p < 0.0001) and Pentacam HR versus Cirrus HD-OCT (p < 0.0001), respectively. There was no difference in CCT measurements between IOLMaster 700 and Cirrus HD-OCT (p = 0.519). The repeatability of keratometry readings (J0 and J45) of IOLMaster 700, Pentacam HR, and iDesign was also high with ICCs ranging from 0.974 to 0.999. The Pentacam HR revealed significantly higher J0 in comparison to IOLMaster 700 (p = 0.009) and iDesign (p = 0.041); however, no significant difference was between IOLMaster 700 and iDesign (p = 0.426). Comparison of J45 showed no significant difference between IOLMaster 700, Pentacam HR, and iDesign. These results were in accordance with Bland-Altman plots. Conclusion. In clinical practice, the devices analyzed should not be used interchangeably due to low agreement regarding CCT as well as keratometry readings.

Comparative analysis of the efficacy of astigmatic correction after wavefront-guided and wavefront-optimized LASIK in low and moderate myopic eyes

AIM

To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis (LASIK) in eyes with myopic astigmatism using wavefront-guided (WFG) and wavefront-optimized (WFO) ablation profiles.

METHODS

Prospective study included 221 eyes undergoing LASIK: 99 and 122 eyes with low and moderate myopic astigmatism (low and moderate myopia groups). Two subgroups were differentiated in each group according to the ablation profile: WFG subgroup, 109 eyes (45/64, low/moderate myopia groups) treated using the Advanced CustomVue platform (Abbott Medical Optics Inc.), and WFO subgroup, 112 eyes (54/58, low/moderate myopia groups) treated using the EX-500 platform (Alcon). Clinical outcomes were evaluated during a 6-month follow-up, including a vector analysis of astigmatic changes.

RESULTS

Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group (P≤0.041). Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups (P≤0.003). In moderate myopia group, a higher percentage of eyes with a postoperative cylinder ≤0.25 D was found in the WFG subgroup (90.6% vs 65.5%, P=0.002). In low and moderate myopia groups, the difference vector was significantly higher in the WFO subgroup compared to WFG (P<0.001). In moderate myopia group, the magnitude (P=0.008) and angle of error (P<0.001) were also significantly higher in the WFO subgroup. Significantly less induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups (P≤0.006).

CONCLUSION

A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK.

Comparison and analysis of FDA reported visual outcomes of the three latest platforms for LASIK: wavefront guided Visx iDesign, topography guided WaveLight Allegro Contoura, and topography guided Nidek EC-5000 CATz

Purpose

To compare and analyze the differences in visual outcomes between Visx iDesign Advanced WaveScan Studio™ System, Alcon Wavelight Allegro Topolyzer and Nidek EC-5000 using Final Fit™ Custom Ablation Treatment Software from the submitted summary of safety and effectiveness of the US Food and Drug Administration (FDA) data.

Methods

In this retrospective comparative study, 334 eyes from Visx iDesign, 212 eyes from Alcon Contour, and 135 eyes from Nidek CATz platforms were analyzed for primary and secondary visual outcomes. These outcomes were compared via side-by-side graphical and tabular representation of the FDA data. Statistical significance was calculated when appropriate to assess differences. A P-value <0.05 was considered statistically significant.

Results

The mean postoperative uncorrected distance visual acuity (UDVA) at 12 months was 20/19.25±8.76, 20/16.59±5.94, and 20/19.17±4.46 for Visx iDesign, Alcon Contoura, and Nidek CATz, respectively. In at least 90% of treated eyes at 3 months and 12 months, all three lasers showed either no change or a gain of corrected distance visual acuity (CDVA). Mesopic contrast sensitivity at 6 months showed a clinically significant increase of 41.3%, 25.1%, and 10.6% for eyes using Visx iDesign, Alcon Contoura, and Nidek CATz, respectively. Photopic contrast sensitivity at 6 months showed a clinically significant increase of 19.2%, 31.9%, and 10.6% for eyes using Visx iDesign, Alcon Contoura, and Nidek CATz, respectively.

Conclusion

FDA data for the three platforms shows all three were excellent with respect to efficacy, safety, accuracy, and stability. However, there are some differences between the platforms with certain outcome measurements. Overall, patients using all three lasers showed significant improvements in primary and secondary visual outcomes after LASIK surgery.

Visual, aberrometric, photic phenomena, and patient satisfaction after myopic wavefront-guided LASIK using a high-resolution aberrometer

Purpose

The purpose of this study was to evaluate the visual, refractive, and aberrometric outcomes as well as the level of patient satisfaction and photic phenomena after myopic laser in situ keratomileusis (LASIK) surgery using wavefront-guided (WFG) ablations based on measurements obtained with a high-resolution aberrometer.

Patients and methods

This study was a prospective analysis including 253 eyes of 127 patients (aged between 19 years and 54 years) undergoing WFG LASIK using the STAR S4 IR Excimer Laser System combined with the iDesign System and iFS Femtosecond Laser. Visual, refractive, and aberrometric outcomes during a 2-month follow-up as well as patient satisfaction and photic phenomena were evaluated by means of a questionnaire.

Results

A total of 85% (215/253) and 99% (251/253) of eyes achieved a postoperative (Postop) uncorrected distance visual acuity of 20/16 and 20/20, respectively, and all eyes achieved an uncorrected distance visual acuity of 20/25. Postop spherical equivalent values were within ±0.25 D and ±0.50 D in 97% and 100% of eyes, respectively. Likewise, manifest cylinder was <0.25 D in 97% (245/253) of eyes. A statistically significant reduction was found in the total root mean square (P<0.001) and in the level of primary spherical aberration (P=0.001). Postop difficulties related to vision were graded as minimal, with low levels of photic phenomena and high levels of patient satisfaction. The level of difficulty to perform daily activities and the level of glare perceived by patients while driving car were significantly decreased (P<0.001).

Conclusion

WFG LASIK surgery using the technology evaluated is predictable and effective for the correction of myopia and leads to high levels of patient satisfaction.

Comparison of short-term refractive surgery outcomes after wavefront-guided versus non-wavefront-guided LASIK

PURPOSE

To evaluate and compare visual and refractive outcomes after laser-assisted in situ keratomileusis (LASIK) surgery for the correction of myopia or myopic astigmatism using 3 different treatment protocols.

METHODS

We included 736 eyes of 369 patients (age 18-62 years) divided into 3 groups: 235 eyes of 118 patients (MEL80 group) undergoing LASIK using optimized aspheric ablation profiles (MEL80 excimer laser; Carl Zeiss Meditec), 248 eyes of 124 patients (Wavescan group) undergoing wavefront-guided (WFG) LASIK (STAR S4IR excimer laser + Wavescan aberrometer; Abbott Medical Optics), and 253 eyes of 127 patients (iDesign group) undergoing WFG LASIK (STAR S4IR excimer laser + iDesign system; Abbott Medical Optics). Visual and refractive outcomes were evaluated 2 months after surgery.

RESULTS

A total of 91% (215/235), 95% (237/248), and 99% (251/253) of eyes achieved a postoperative uncorrected distance visual acuity of 0.0 logMAR (≈20/20) in the MEL80, Wavescan, and iDesign groups, respectively. Postoperative spherical equivalent (SE) was within ±0.5 D in 95% (223/235), 98% (242/248), and 100% (253/253) of eyes in these same 3 groups, respectively. Likewise, manifest cylinder was below 0.50 D in 95% (223/235), 97% (241/248), and 100% (253/253) of eyes. Significant differences in postoperative SE and cylinder were found between the MEL80 and iDesign groups (p&lt;0.05).

CONCLUSIONS

All evaluated LASIK treatment protocols are predictable and effective for the correction of myopia. The treatment planned with a high resolution aberrometer obtained the best postoperative refractive outcomes.

Flap lift and photorefractive keratectomy enhancements after primary laser in situ keratomileusis using a wavefront-guided ablation profile: Refractive and visual outcomes

PURPOSE

To analyze results of wavefront-guided laser vision correction retreatments performed either by lifting the original flap or by surface ablation over the flap.

SETTING

Optical Express, Glasgow, United Kingdom.

DESIGN

Retrospective case series.

METHODS

This retrospective study included patients grouped according to whether they had flap lift enhancement or photorefractive keratectomy (PRK) performed over the LASIK flap. All retreatment procedures were performed with the Visx Star S4 IR excimer laser with wavefront-guided ablation profile derived from the iDesign aberrometer. Visual acuities, refractive outcomes, vector analysis of refractive cylinder and complications were analyzed in this study. The results of the last available clinical visit are presented.

RESULTS

This retrospective study included 290 eyes of 202 patients divided into 2 groups: 119 eyes that had flap lift enhancement (Group A), and 171 eyes in which photorefractive keratectomy (PRK) was performed over the LASIK flap (Group B). The mean follow-up was 4.0 ± 1.9 months in Group A and 4.2 ± 1.6 in Group B. The mean postoperative manifest spherical equivalent was -0.01 ± 0.35 D and +0.06 ± 0.39 D in Groups A and B, respectively. The percentage of eyes with postenhancement UDVA 20/20 or better was 87.4% in Group A and 79.5 % in Group B (P = .09). In Group A, 22 eyes (18.5%) developed epithelial ingrowth, of which surgical intervention was required in 2 eyes (1.7%). Grade 1 or less haze was noted in 9 (5.3%) eyes in Group B, and resolved in all cases within the first 6 postoperative months.

CONCLUSION

Both retreatment techniques were considered to be effective, predictable, and safe.

FINANCIAL DISCLOSURE

Steven C Schallhorn MD is a consultant to Abbott Medical Optics and Zeiss, and Global Medical Director for Optical Express. None of the other authors have a financial or proprietary interest in the products and materials presented in this paper.

Outcomes of wavefront-guided laser in situ keratomileusis using a new-generation Hartmann-Shack aberrometer in patients with high myopia

PURPOSE

To evaluate refractive and visual outcomes of wavefront-guided laser in situ keratomileusis (LASIK) to correct high myopia using a new Hartmann-Shack aberrometer.

SETTING

Optical Express, Glasgow, United Kingdom.

DESIGN

Retrospective noncomparative case series.

METHODS

Data of eyes that had wavefront-guided LASIK for high myopia and myopic astigmatism (spherical equivalent [SE] between -6.00 diopters [D] and -10.25 D, up to 5.00 D of cylinder) were analyzed. The treatment profile was derived from a new-generation Hartmann-Shack aberrometer (iDesign Advanced Wavescan). Visual acuities, refractive outcomes, vector analysis of refractive cylinder, and patient satisfaction were assessed. Three-months data are presented.

RESULTS

Data were obtained for 621 eyes. The mean manifest SE reduced from -7.28 D ± 1.05 (SD) (range -10.25 to -6.00 D) preoperatively to -0.09 ± 0.44 D (range -2.13 to +1.38 D) at 3 months. The mean manifest cylinder changed from -1.02 ± 0.82 D (range -5.00 to 0.00 D) to -0.27 ± 0.33 D (range -1.75 to 0.00 D) postoperatively. The percentage of eyes achieving an uncorrected distance visual acuity 20/20 or better was 82.4% monocularly and 92.5% binocularly. The mean correction ratio of refractive cylinder was 1.02 ± 0.48, and the mean error of angle was -0.29 ± 14.56 degrees. A postoperative questionnaire revealed high satisfaction with the outcomes of the procedure, with low scores for night-vision phenomena.

CONCLUSION

The results in this study were promising in terms of safety, efficacy, and predictability in eyes with high degrees of myopia.

FINANCIAL DISCLOSURE

Dr. Schallhorn is a consultant to Abbott Medical Optics, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

Femtosecond Laser-assisted Wavefront-guided LASIK Using a Newer Generation Aberrometer: 1-Year Results

PURPOSE

To evaluate long-term outcomes of wavefront-guided LASIK with a new advanced aberrometer.

METHODS

Fifty eyes of 25 LASIK candidates with myopia and/or astigmatism underwent aberrometry (iDesign Advanced WaveScan; Abbott Medical Optics, Santa Ana, CA), femtosecond laser-assisted flap creation, and excimer ablation. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SEQ), and astigmatism outcomes were measured at 1, 3, 6, and 12 months postoperatively.

RESULTS

The sphere, cylinder, and SEQ were -4.29 ± 1.94, -0.75 ± 0.76, and -4.67 ± 2.01 diopters (D), respectively, preoperatively and 0.03 ± 0.13, -0.09 ± 0.13, and -0.02 ± 0.14 D, respectively, 12 months postoperatively (P < .001). The postoperative log-MAR CDVA (-0.07 ± 0.09) and UDVA (-0.04 ± 0.09) were better than the preoperative logMAR CDVA (0.07 ± 0.10) (P < .01). Ninety-four percent achieved a 12-month logMAR UDVA of 0.0 or less (20/20 or better Snellen) and 100% achieved 0.3 or less (20/40 or better Snellen), compared to a preoperative logMAR CDVA of 0.0 or worse in 54% and 0.3 or less in 100%. Postoperative SEQ was within ±0.50 D in 98%. The regression plot for achieved (y) vs intended (x) correction at 12 months was (y = 0.98 × - 0.09, R(2) = 0.99, P < .001). No cases lost CDVA. The target and 12-month surgically induced astigmatisms (TIA and SIA) were 0.91 ± 0.75 and 0.82 ± 0.70, respectively. The regression plot between them was SIA = 0.91 × TIA - 0.01 (R(2) = 0.95, P < .001). The angle of error was -0.29° ± 12.6° and index of success was 0.13 ± 0.25. There was only a mild, nonsignificant increase of higher-order aberrations after surgery, and the postoperative wavefront was stable on follow-up.

CONCLUSIONS

Wavefront-guided LASIK with iDesign aberrometry appears to be safe and effective in this long-term, consecutive case series.

Comparison of Measurements and Clinical Outcomes After Wavefront-Guided LASEK Between iDesign and WaveScan

PURPOSE

To compare the measurements of refractive errors and ocular aberrations obtained using iDesign and WaveScan (Abbott Medical Optics, Inc., Santa Ana, CA), and to compare surgical outcomes of wavefront-guided LASEK using ablation profiles based on both aberrometers.

METHODS

Ninety myopic eyes of 45 normal patients were evaluated using both the iDesign and WaveScan to measure spherical and cylindrical errors, spherical equivalents, and Zernike coefficients of ocular aberrations. Wavefront-guided LASEK was performed in a different group of 59 eyes of 30 patients divided into two groups, the iDesign and Wavescan groups. The clinical outcomes between the two groups including uncorrected visual acuity, refractive errors, contrast sensitivity, and ocular aberration were compared at 1, 3, and 6 months postoperatively.

RESULTS

The iDesign produced significantly higher myopic values for refractive errors than the WaveScan, as well as significantly lower levels of total higher order, third, fourth, and fifth order root mean square values and Zernike coefficients of vertical coma and spherical aberration. At postoperative 1, 3, and 6 months, there were no statistically significant differences between the two groups in terms of uncorrected visual acuity and remaining refractive errors. The percentages of patients with spherical equivalents within ±1.00 and ±0.50 diopters of emmetropia were 100% (29 eyes) and 75.9% (22 eyes), respectively, in the iDesign group and 96.7% (29 eyes) and 70.0% (21 eyes), respectively, in the WaveScan group. Mesopic contrast sensitivity values were significantly higher, and the change in root mean square values for spherical aberration was significantly lower in the iDesign group.

CONCLUSIONS

There were significant differences between the iDesign and the WaveScan in the measurements of refraction and ocular aberrations. Wavefront-guided LASEK based on an ablation profile from the iDesign demonstrated comparable refractive predictability with the WaveScan group, resulting in minimal physician adjustment and superior postoperative visual quality.

Clinical outcomes of wavefront-guided laser in situ keratomileusis to treat moderate-to-high astigmatism

PURPOSE

The purpose of this study was to evaluate the refractive and visual outcomes of wavefront-guided laser in situ keratomileusis (LASIK) in eyes with myopic astigmatism and cylindrical component ≥2.0 diopter (D).

METHODS

In this retrospective study, 611 eyes that underwent LASIK for simple or compound myopic astigmatism were analyzed. Preoperative refractive cylinder ranged from -2.00 D to -6.00 D (mean -2.76±0.81 D), and the sphere was between 0.00 D and -9.75 D (mean -2.79±2.32 D). Predictability, visual outcomes, and vector analysis of changes in refractive astigmatism were evaluated.

RESULTS

At 3 months after LASIK, 83.8% of eyes had uncorrected distance visual acuity of 20/20 or better, 90.3% had manifest spherical equivalent within ±0.50 D, and 79.1% had residual refractive cylinder within ±0.50 D of intended correction. The mean correction ratio for refractive cylinder was 0.92±0.14, the mean error of angle was -0.45°±2.99°, and the mean error vector was 0.37±0.38 D. A statistically significant correlation was found between the error of magnitude (arithmetic difference in the magnitudes between surgically induced refractive correction and intended refractive correction) and the intended refractive correction (r=0.26, P<0.01).

CONCLUSION

Wavefront-guided LASIK for the correction of myopic astigmatism is safe, effective, and predictable.